Elevating ladder scaffold



Nov. 4, 1952 N. H. RECTOR 2,616,769

ELEVATING LADDER SCAFFOLD Filed D80. 29, 1947 1 2 SHEETS-SHEET1 INVEN TOR. NELSON H. RECTOR ATTORN Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE V 2,616,769

E EvA'rmG LADDER SCAFFOLD Nelson Rector, Atlanta, Ga. Application December 29, 1947, Serial No. 794,285

The present invention relates to a scaffold device, and more particularly to a scaffold structure in combination with a pair of rolling ladders adapted to be moved along the side .of a building.

The primary object of the present invention is to provide an adjustable scaffold structure including a platform supported by'two ladders adapted to roll along the'side of a building and which additionally furnish means of leaving or entering the building in the event of an emergency, such as fire.

'Another object. is to provide a scaffold which is quickly and easily adjustable either upwardly or downwardly. V I I a A furtherobject is to provide a scaffolddevice with a, simple and effective means .to automatically lock the scaffold against downward movement, preferably in combination with means to release said lock means to permit selective downward movement of the scaffold. v

In one of its aspects, the present invention em.- braces an adjustable scaffold device for use with apair of ladders provided with rungs, with said device including a platform provided with a slot at each end portion extending lengthwise of the platform to vertically receive a ladder, with a brace for each ladder secured to said platform at said-slots therein, with said brace being adapted to slidably engage over a ladder, a pair of lock rods for each ladder, with said lock rods being pivotally secured to the underside of said platform and adapted to have the inner end portions thereof fit over a suitable rung in the ladder and a stop block for each lock rod secured to the underside of said platform and bearing against said rod when the scaffold device is in locked position.

Other and further objects and advantages of the present invention will be apparent from the following description thereof and from. the claims appended thereto.

. In the drawing wherein like numerals refer to like or corresponding parts throughout the several views:

Figure 1 is a fragmentary front elevation of a building showing the scaffold device disposed on a pair of rolling ladders, and embodying the features of the present invention;

Figure 2 is a fragmentary sectional view taken substantially along the line 2-2 of Figure l, in the direction of the arrows;

Figure 3 is a sectional view taken along the line 3-3 of Figure 2, in the direction of the arrows;

Figure 4 is a sectional view taken along the line 4-4 of Figure 2, in the direction of the arrows;

Figure 5 is an enlarged fragmentary detail showing means for automatically looking a ladder against downward vertical movement, and means to release said lockingmeans; and

Figurefi is a detail showing the spring-operated 'zcla ims. (o1. ant-31) 2 plunger for disengaging the means for locking the scaffold device against downward movement.

Referring now to the drawing, the numeral It] generally represents a building, such as an apartment house, hotel, hospital, oflice building, asylum, or similar building, upon which is mounted a rolling ladder assembly, as more fully set forth in my copending patent application, Serial No. 743,645, filed April 24, 1947. The rolling ladder assembly generally includes a track ll disposed around the top portion of the building to, with a wheel assembly l2 and I3 adapted to roll upon the track II, with ladders l4 and I5 respectively secured to said wheel assemblies I2 and I3 in any suitable manner, so that ladders l4 and I5 may roll as a unit along the track H.

The present invention concerns itself with a scaffold device, preferably used in combination with a pair of rolling ladders I4 and I5, and generally comprises a platform l6 which is provided with slots l1 and I8 at opposite end portions of the platform It, with said slots l1 and I8 extending lengthwise of said platform [6. Ladders l4 and 15 are adapted to fit into slots l1 and [8 respectively, so that the platform i6 is free to move upwardly or downwardly along the length of said ladders l4 and I5.

The structure of the present scafford device is identical With relation to ladders l4 and' I5 and, therefore, the description will be made only as to one. The ladder l5 has the usual rungs l9 extending throughout the vertical length of said ladder. A brace member generally represented by the numeral 20 is mounted on the upper side of platform [6 and is secured thereto by means of bolts 2|, or the like. Said brace 29 generally includes a substantially inverted U -shaped bracket fastened to the central portion of an apertured bar 22, which fits over the ladder l5, and is moved upwardly or downwardly with the platform 16. The brace 20 is of importance to keep the platform l6 level when it is inuse, that is to say, to prevent it from tipping if weight is shifted to the outer edges thereof.

On the underside of the platform Hi, there is mounted means for automatically locking :the scaffold device against downward movement, with said locking means leaving the platform free to be moved upwardly. Said locking means generally include a pair of lock rods 23' and 24 which are pivoted to'the underside of platform It. The rod 23 is secured to arotatable shaft 25 which extends substantially throughout the length of platform [6 on the underside thereof being supported by means of roll bearings 28, which are secured to the platform It.

. The shaft 25 is connected to the lock rod 23 and to the lock rod which corresponds to'lock rod 23 in the other pair of lock rods which operate in connection with rolling ladder l4. Likewise, the 1001: rod 24 is connected to shaftZl so that when shaft 21 is rotated throughout a limited form l6 against downward movement.

degree, lock rod 24 and its corresponding lock rod are moved together simultaneously.

To operate the shafts 25 and 27, and :the .lock rods 23 and 24, there is provided a plunger 29 which extends above the platform f6, and is disposed near the rolling ladder I5. is provided with a spring 33 so that when the plunger 29 is depressed, the spring will automatically move it back into a raised position. The plunger 29 generally includes anelongated rack bar 3! which fits through a suitable opening in the platform It with said rack barSl being provided with teeth engaging the teeth of a pair of swingable elements 32 and 33, which elements 32 and 33 are respectively secured to the shafts 2.5 and 2?, so that a depression of the plunger 23 will cause the element 32 to swing inone direction, and element 33 to swingin the opposite .direction, to thereby rotate shafts 25 and 12-7 in opposite directions and to swing-lock rods 23 and 24 away from a rung'in the ladder, when said scaffold device'is so positioned that the lock rods 23 and 2 3 are disposed between rungs in the ladder.

The lock rodsdt and 2d are each provided-with a counterweight 23a and 24a at the outer end portionsthereof/which counterweights 23a and 24a cause the lock rods 23 and 24 to automatically swing into engagement over the rungs of'the ladders, as the scaffold platform is moved upwardly. As the lock rods '23 and 24 engage over the rung .of .the ladder, .a slight -lowering of the platform E 6 will cause the rods'23 and'24 .to engage stop :blocks $2.311 and Z lb secured to the underside of the platform it by means .of "bolts 23c and 250.

The scaffold device is provided with the con ventional block and tackle structure generally indicated by the numeral 34 with reference to ladder l5, and 35 with reference to ladder M. The block and tackle structure includes the usual pulley arrangement, having the free lines and 3! for raising and lowering the platform It. It is to be noted that the upper portion of the block and tackle arrangement is secured to the upper rung of the ladders l4 and I5, so that the platform 16 and the rolling ladders l4 and I5 may be moved along the side of the building as a unit. The block and tackle structure forms no part of the present invention per se, and therefore it .has not been described in detail.

In operation, the scaffold device may be raised by means of the ropes 36 and 31 to any desired height on the ladders l4 and I5. When the proper position is reached, the lock rods '23 and 24, in each pair, fall over an appropriate rung in the ladder and upon a slight lowering of the platform [6, the lock rods 23 and 24 bear against the stop blocks 23b and 241) respectively, to thereby lock the platform It against downward movement. Thus it can be seen that I have provided automatic means for locking the plat- When it is desired to move the platform .16 downwardly, and to release the lock rods 23 and 24 from locked position, it is only necessary .to move the platform I6 to a position between *rungs on the ladders I4 and I5, by means of pulley ropes and 31.

With the lock rods 23 and 2.4 in a position intermediate to rungs of the ladder, the operator then depresses the plunger 29 to operate shafts 25 and 21, and to swing lock rods 23 and 24 away from the rungs of the ladders, so that the platform I6 may be moved downwardly by means The plunger 23 4 of the block and tackle arrangement independent of the automatic locking means.

It is to be understood that my invention includes an adjustable scaffold device for use with a pair of ladders with means for automatically locking the scaffold device against downward movement, and preferably in combination with means to release said automatic locking means aforesaid so that the scaffold device may be selectively lowered through the operation of a conventional block and tackle arrangement.

Various modifications of the present invention will be apparent to those skilled in the art without departing from the spirit thereof, and it is therefore desired to beilimited only by the scope of the appended claims.

What I claimis: I

'1. An adjustable scaffold device comprising a pair of spaced apart rolling ladders each pro.- vided with rungs, a platform provided with a slot at each .end portion thereof extending lengthwise of the platform, a ladder vertically disposed in each of said slots, a pair of lock rods for each ladder adapted to engage the rungs of the ladder to limit downward movement of said platform, said locks being pivotally secured to the underside of said platform and having a portion .thereof fit over a suitable rung in said ladder, the axes of said lock rod pivots being substantially parallel to .said rungs, said lock rods e tendin su tantially perpendicularly to their pivotal axes in ,a direction toward said rungs and each having a portion extending beyo d t run means ope ated from said Platf m to si u taneous y swin the o k s i bo pai th r of a y from a runs in each ladder, and said last mentioned means including a plunger provided with a rack having teeth lengthwise of the platform, a ladder vertically disposed in each of said slots, a pair of oppositely disposed lock rods for each ladder, each of said lock rods being pivotally secured to the underside of said platform at opposite sides thereof and extending towards each other so that their free end portions overlap and have their under surfaces engaging .over a suitable rung in a ladder, each of said lock rods being weighted at its opposite end, and a stop .block for each of said lock rods secured to the underside of said platform and bearing against the upper surface of said rod when the scaffold device is in locked position.

NELSON H. HECTOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 292,265 Stoddard Jan. 22, 1884 737,187 Williams Aug. 25, 1903 837,006 Spraull Nov. 27, 1906 921,117 Jones May 11, 1909 FOREIGN PATENTS Number Country 7 Date 16,698 Great :Britain Aug. 17,1905 

